DEA-C01 Data Operations and Support Practice Question
A company uses Amazon Redshift for data warehousing. They notice that query performance has degraded over time. Which maintenance operation should be performed to improve performance?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Run the VACUUM command
The VACUUM command re-sorts rows according to the sort key and reclaims disk space from deleted rows, which can improve query performance. Option B is incorrect because dropping and recreating the table is a heavy operation that requires redefining the table and reloading data; it is not a standard maintenance operation for performance. Option C is incorrect because Redshift uses sort keys and distribution keys instead of indexes; there is no REINDEX command in Redshift. Option D is incorrect because the ANALYZE command updates table statistics to help the query optimizer, but it does not physically reorganize the data; thus it may help with query planning but does not directly improve performance from data fragmentation.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Run the VACUUM command
Why this is correct
Correct. VACUUM re-sorts rows and reclaims space, improving performance.
- ✗
Drop and recreate the table
Why it's wrong here
Incorrect. Dropping and recreating the table deletes data and is not a maintenance operation.
- ✗
Run the REINDEX command
Why it's wrong here
Incorrect. REINDEX rebuilds indexes, but Redshift uses sort keys, not indexes.
- ✗
Run the ANALYZE command
Why it's wrong here
Incorrect. ANALYZE updates statistics but does not physically reorganize data.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DEA-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DEA-C01 exam.